An ultra-wideband and wide-angle hexagonal electromagnetic stealth metamaterial is designed by optimally combining rhombus-carbon tiles on the top of and on the intermediate surface of a foam substrate by utilizing the genetic algorithm. For the first time, a stealth mechanism is unveiled that converts parts of absorptive surface plasmon polaritons induced in an ultra-wide bandwidth from three axial periodic edges and slots for both the transverse electric (TE) and the transverse magnetic (TM) polarizations into radiative ones that have undetectable polarized states for conventional antenna systems. From the measurement, the − 10 dB reflectance bandwidth (BW) is achieved from 1 to 11.66 GHz of which the fractional BW is 168.4% for the normal incidence. Besides, the − 10 dB fractional BW of 49.95% is confirmed for both the TE and the TM polarizations with the incident angle θ from 0° to 45°. Most importantly, the fractional BW is reached to 64.83% for the TE polarization with θ from 0° to 60° which has not been achieved based on square-shape metamaterial absorbers. The design strategy could pave the way to escape from long captivated stealth concepts, i.e., absorbing power, changing the angle of reflection, or shifting the frequency band.

Four-dimensional (4D) bioprinting holds significant promise in precision medicine, enabling the emulation of dynamic changes in the human body and tissues to provide personalized treatments. Smart materials for 4D printing (i.e., responsive to specific stimuli) should exhibit properties, such as biodegradability, biocompatibility, and ease of processing, while also enabling the prediction of time-dependent behavior in programmed geometry. This study focused on the development of a body temperature-responsive shape-memory polymer (SMP). The thermal properties of the SMP were analyzed, and its biodegradability and biocompatibility were assessed through structures fabricated by three-dimensional printing techniques. The simulation calculated with this finite element (FE) solution was in good agreement with those measured in experiments. The findings contribute to our understanding of the behavior of SMP under various conditions, validating the effectiveness of the developed material for potential applications in precision medicine and 4D bioprinting. It has the potential for use in medical devices, such as catheters, stents, and artificial scaffolds, prepared by 4D bioprinting.